This piece belongs to Diocletian's regnal years L A and L B — his first and second years as counted by the Alexandrian calendar, which began each cycle on 29 August. Alexandria's mint was among the most prolific provincial operations in the empire, and under Diocletian it served a Egypt-specific monetary system that remained partially insulated from the broader Roman coinage until his currency reforms of 296 AD effectively absorbed it. The billon content by this point was dramatically debased from earlier tetradrachm standards, a decline that had accelerated through the third-century crisis.
This piece belongs to Diocletian's regnal years L A and L B — his first and second years as counted by the Alexandrian calendar, which began each cycle on 29 August. Alexandria's mint was among the most prolific provincial operations in the empire, and under Diocletian it served a Egypt-specific monetary system that remained partially insulated from the broader Roman coinage until his currency reforms of 296 AD effectively absorbed it. The billon content by this point was dramatically debased from earlier tetradrachm standards, a decline that had accelerated through the third-century crisis.